Bottom line, mitsu did this for a reason. Still good DIY though

 

My guess would be that the factory was protecting the plastic duct from the intense heat of the turbo, thus ensuring in wouldn't warp when at rest.

 

Carbon Fibre duct here I come :-P I just removed mine entirely....and the metal shields behind the hood vents.

Any of you guys that track your cars, (and that have removed the shield), notice any problems with the NACA duct? Thanks!

verkion